Preoperative diagnosis of pancreatic cystic lesions remains a difficult problem in clinical practice. At present, the treatment planning in pancreatic cystic neoplasms is significantly restricted by the limited preoperative diagnosis. Ultrasonography (US), multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) are the conventional modalities in imaging of pancreatic cystic neoplasms, but by these methods the diagnostic accuracy still remains compromised. Furthermore, recently encouraging results have been obtained in pancreatic cystic neoplasms using 18F-fluoro-2-deoxyglucose positron emission tomography (18F-FDG-PET) The aim of the current project is to evaluate the possibility to enhance the diagnostic accuracy by using the combined 18F-FDG-PET-CT imaging in patients with pancreatic cystic neoplasms by combining PET-CT with MRI and MDCT.